Tore Lydersen

Choice of timeout from fixed-time schedules: Comparison of two procedures

Behavioural Processes, Jul 1, 1997

Four rats obtained food on fixed-time (FT) 1-, 4-, and 16-min schedules. During FT schedules, a l... more Four rats obtained food on fixed-time (FT) 1-, 4-, and 16-min schedules. During FT schedules, a lever press produced a timeout period during which food could not be delivered. When timeout was in effect, a lever press ended the timeout period and reinstated the FT schedule. In different conditions, the timing of the FT interval either stopped for the duration of the timeout period (Stop condition) or the timing of the FT interval continued during timeout (No Stop condition). The percentage of session time spent in timeout periods increased as the time between food deliveries increased regardless of whether or not timing of the FT interval stopped during timeout. The timeout percentage was larger on Stop than No Stop conditions if the obtained interfood interval was also longer. The rate of initiation of timeout periods tended to increase from FT 1-min to FT 4-min schedules, and then not increase further or decrease on FT 16-min. The mean time per timeout period tended to be similar on FT 1-and FT 4-min schedules and then increase on FT 16-min. A given percentage of session time spent in timeout periods appears to be due to interactions between rate of timeout, duration of timeout periods and interfood interval. The data are not consistent with the suggestion that timeout initiation represents escape from aversive aspects of intermittent reinforcement. Instead, choice of timeout shares some of the properties of facultative behaviors.

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Schedule-induced timeout: Effects of timeout-contingent delayed reinforcement

Behavioural Processes, Apr 1, 1994

Rats&#39; lever pressing turned off stimuli associated with various response-independent fixe... more Rats&#39; lever pressing turned off stimuli associated with various response-independent fixed-time schedules of food delivery and produced a timeout period during which food delivery could not occur. A lever press during timeout turned on the schedule-associated stimuli and reinstated the fixed-time schedule. Every response that produced timeout ended the timing of fixed time intervals; timeout terminating responses started the timing of fixed-time schedules over again. The percentage of session time spent in timeout periods generally increased as the rate of food delivery decreased. When food delivery could not occur, about half of the session time was spent in the stimulus condition formerly associated with timeout. The majority of timeout periods were initiated after 15 seconds or more had lapsed since the last food delivery. When timeout periods could not be produced, lever pressing rates either decreased or were not affected. The rate of food delivery appeared to be a primary determinant of time spent in timeout periods. The results may be inconsistent with interpretations emphasizing escape from aversive aspects of schedules of positive reinforcement.

Timeout induced by differential-reinforcement-of-low-rate schedules

Behavioural Processes, Dec 1, 1992

Three rats pressed a lever for food on differential-reinforcement-of-low-rate (DRL) schedules ran... more Three rats pressed a lever for food on differential-reinforcement-of-low-rate (DRL) schedules ranging from 16 s to 96 s. During DRL performance, a response to a second lever turned off chamber illumination and produced a timeout period during which food could not be obtained. During timeout periods, a response to the second lever reinstated the DRL schedule and associated chamber illumination. The percentage of session time spent in timeout periods increased as the DRL schedule was lengthened and decreased when the schedule was shortened. Changes in timeout percentage were primarily due to changes in the mean time per timeout rather than to changes in the rate of initiation of timeout periods. Extinction increased the timeout percentage. Elimination of the timeout contingency decreased the response rate to the timeout lever, but did not systematically affect DRL lever pressing. The rate of reinforcement appeared to be a primary determinant of the percent of session time spent in timeout periods.

Choosing Staff Members Reduces Time in Mechanical Restraint Due to Self-Injurious Behaviour and Requesting Restraint

Mental Handicap Research, Jan 5, 2012

Using mechanical restraints to protect a person who engaged in dangerous self-injury was decrease... more Using mechanical restraints to protect a person who engaged in dangerous self-injury was decreased by manipulation of an establishing operation involving the client choosing the staff person who would work with her. The client was a 28-year-old woman diagnosed with autism, bipolar disorder, static cerebral encephalopathy, moderate intellectual disabilities, hypotonia and musculoskeletal deformities. She had a history of biting herself and further bites could produce irreversible nerve damage. Mechanical restraints were applied when she bit, tried to bite herself or asked for them. When she was allowed to choose staff members, the use of mechanical restraint decreased. Reducing the time spent in mechanical restraint by giving the client a choice of staff members who would work with her demonstrates that such a choice may be an establishing operation. The usefulness of cumulative records and scatterplots to evaluate changes in the occurrence of self-injurious behaviour (SIB) and associated mechanical restraint is shown as are the advantages of using alternating treatment designs to assess the effectiveness of treatment conditions for someone who exhibits long-term cyclic behaviour.

Effects of Intermittent Reinforcement Upon Fixed-Ratio Discrimination

PsycEXTRA Dataset

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Effects of duration of DRL correlated stimuli on timing and collateral responding

Psychonomic Science, 1972

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Acquisition Under Mixed-Delay and Multiple-Delay Matching-To-Sample

Psychological Reports, 1973

Summsy.-The acqaisition of delayed matching to sample in two groups of pigeons was examined when ... more Summsy.-The acqaisition of delayed matching to sample in two groups of pigeons was examined when three delay values (2, 4, and G sec.) were mixed across trials and when each of the three delay values was correlated with one of three standard stimuli (i.c., multiple delays). Extended training resulted in the acquisition of matching by all multiple-delay Ss, while only one of three mixeddelay Ss showed comparable performance. The one S which acquired matching under the mixed condition emitred standard, specific, delay behaviors. The results suggest that acquisition of delayed matching may be highly dependent upon the availability of some source of delay-stimuli that are consistently correlated with standard stimuli.

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Fixed-Ratio Discrimination: Comparison of Spatial and Nonspatial Choice Procedures

Perceptual and Motor Skills, 1976

3 pigeons were trained on a conditional discrimination in which fixed-ratio 10 and fixed-ratio 20... more 3 pigeons were trained on a conditional discrimination in which fixed-ratio 10 and fixed-ratio 20 were randomly scheduled on the center of 3 response keys. Reinforcement was contingent upon the choice of a green side key on fixed-ratio 10 trials and upon a red side key on fixed-ratio 20 trials. Performance was compared on alternating spatial and nonspatial sessions. During spatial sessions, red was always presented on the left-side key and green was always presented on the right. During nonspatial sessions, the location of the two side-key colors was randomized across trials. Accuracy of spatial choice was higher than during nonspatial choice.

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Effects of response-produced stimuli upon conditional discrimination performance1

Journal of the Experimental Analysis of Behavior, 1974

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Choice of Timeout During Response Independent Food Schedules

Journal of the Experimental Analysis of Behavior, 1980

Rats' lever pressing terminated visual or auditory stimuli associated with fixed-time or variable... more Rats' lever pressing terminated visual or auditory stimuli associated with fixed-time or variable-time schedules of food delivery and produced a timeout period during which food delivery could not occur. Lever pressing during a timeout period reinstated the foodassociated stimuli and again permitted food delivery according to the fixed-time or variabletime schedules. The mean interfood interval ranged from 1 minute to 16 minutes (variabletime schedules) or 32 minutes (fixed-time schedules); the timer controlling schedule intervals did not stop during timeout periods. The percentage of session time spent in timeout increased when the mean interfood intervals were lengthened and decreased when the mean interfood intervals were shortened. Timeouts were initiated most frequently about half way between successive food deliveries (fixed-time schedules) or after 15 seconds or more had lapsed since the last food delivery (variable-time schedules). Elimination of food delivery increased the percentage of session time spent in timeout, and elimination of the timeout contingency decreased lever press rates. When timeout was produced only when the lever was held in the depressed position, little time was spent in timeout. The main determinants of timeout initiation and termination appeared to be the rate of food delivery, freedom of movement during timeout, and the stimulus change associated with initiation and termination of timeout.

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Fixed-ratio discrimination: effects of intermittent reinforcement

Journal of the Experimental Analysis of Behavior, 1977

Four pigeons had discrimination training that required the choice of a left side-key after comple... more Four pigeons had discrimination training that required the choice of a left side-key after completing a fixed-ratio 10 on the center key, and a right side-key choice after fixed-ratio 20. Correct choices were reinforced on various fixed-interval, fixed-ratio, random-interval, and random-ratio schedules. When performance was examined across successive 15-second intervals (fixed-interval and fixed-ratio schedules) accuracy was high in the first 15-second interval, decreased in one or several of the next 15-second intervals, and then increased again as reinforcement was approached. When perforlniance was examined across correct trials on fixed-interval and fixed-ratio schedules, accuracy was lowest immediately after reinforcement, followed by a systematic increase in accuracy as the number of correct choices increased. These patterns were due primarily to errors on fixed-ratio 20 trials. Systematic accuracy patterns did not occur on random-interval or random-ratio schedules. The results indicate that when choice patterns differed on fixed-interval and fixed-ratio schedLules, the differences were due to the method of data analysis.

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Effects of fixed-ratio sample and choice response requirements upon oddity matching1

Journal of the Experimental Analysis of Behavior, 1977

Three pigeons were trained on oddity matching in which either 1, 4, 8, 16, or 32 sample-key obser... more Three pigeons were trained on oddity matching in which either 1, 4, 8, 16, or 32 sample-key observing responses were required to turn off the sample stimuli and turn on the comparison stimuli. Oddity accuracy increased when the observing-response requirement was raised and decreased when the requirement was lowered. Next, while the observing requirement was maintained at one response, the number of responses required to the comparison stimuli was either 1, 4, 8, 16, or 32. Under these conditions, choice was defined as the comparison that first accumulated the required number of responses. In general, increasing the comparison-response requirement decreased accuracy and lowering the comparison requirement increased accuracy. The fixed-ratio observing requirements appeared to facilitate control by stimuli serving an instructional function.

Fixed-ratio discrimination: effects of response-produced blackouts1

Journal of the Experimental Analysis of Behavior, 1974

For three pigeons, reinforcement depended upon a left side-key response after execution of a fixe... more For three pigeons, reinforcement depended upon a left side-key response after execution of a fixed ratio 10 on the center key, and upon a right side-key response after fixed ratio 20. Each response during the fixed ratios produced a 0.5-sec blackout. The time between the first and last response in fixed ratio 10 was then equated with the time between the first and last response in fixed ratio 20 by increasing the blackout duration. The accuracy of side-key choice was disrupted, thereby suggesting that time, rather than number of responses, controlled choice responding. When the time between the first and last response was equated during both ratios, asymptotic accuracy was approximately equal to (two birds) or somewhat higher than (one bird) that obtained previously. The results of probes with intermediate fixed ratios and blackouts suggested that control of side-key choice had transferred from the time between the first and last resnonse in ratios to blackout duration.

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Choosing Staff Members Reduces Time in Mechanical Restraint Due to Self-Injurious Behaviour and Requesting Restraint

Journal of Applied Research in Intellectual Disabilities, 2012

Using mechanical restraints to protect a person who engaged in dangerous self-injury was decrease... more Using mechanical restraints to protect a person who engaged in dangerous self-injury was decreased by manipulation of an establishing operation involving the client choosing the staff person who would work with her. The client was a 28-year-old woman diagnosed with autism, bipolar disorder, static cerebral encephalopathy, moderate intellectual disabilities, hypotonia and musculoskeletal deformities. She had a history of biting herself and further bites could produce irreversible nerve damage. Mechanical restraints were applied when she bit, tried to bite herself or asked for them. When she was allowed to choose staff members, the use of mechanical restraint decreased. Reducing the time spent in mechanical restraint by giving the client a choice of staff members who would work with her demonstrates that such a choice may be an establishing operation. The usefulness of cumulative records and scatterplots to evaluate changes in the occurrence of self-injurious behaviour (SIB) and associated mechanical restraint is shown as are the advantages of using alternating treatment designs to assess the effectiveness of treatment conditions for someone who exhibits long-term cyclic behaviour.

Schedule-induced timeout: Effects of timeout-contingent delayed reinforcement

Behavioural Processes, 1994

Rats&#39; lever pressing turned off stimuli associated with various response-independent fixe... more Rats&#39; lever pressing turned off stimuli associated with various response-independent fixed-time schedules of food delivery and produced a timeout period during which food delivery could not occur. A lever press during timeout turned on the schedule-associated stimuli and reinstated the fixed-time schedule. Every response that produced timeout ended the timing of fixed time intervals; timeout terminating responses started the timing of fixed-time schedules over again. The percentage of session time spent in timeout periods generally increased as the rate of food delivery decreased. When food delivery could not occur, about half of the session time was spent in the stimulus condition formerly associated with timeout. The majority of timeout periods were initiated after 15 seconds or more had lapsed since the last food delivery. When timeout periods could not be produced, lever pressing rates either decreased or were not affected. The rate of food delivery appeared to be a primary determinant of time spent in timeout periods. The results may be inconsistent with interpretations emphasizing escape from aversive aspects of schedules of positive reinforcement.

Timeout induced by differential-reinforcement-of-low-rate schedules

Behavioural Processes, 1992

Three rats pressed a lever for food on differential-reinforcement-of-low-rate (DRL) schedules ran... more Three rats pressed a lever for food on differential-reinforcement-of-low-rate (DRL) schedules ranging from 16 s to 96 s. During DRL performance, a response to a second lever turned off chamber illumination and produced a timeout period during which food could not be obtained. During timeout periods, a response to the second lever reinstated the DRL schedule and associated chamber illumination. The percentage of session time spent in timeout periods increased as the DRL schedule was lengthened and decreased when the schedule was shortened. Changes in timeout percentage were primarily due to changes in the mean time per timeout rather than to changes in the rate of initiation of timeout periods. Extinction increased the timeout percentage. Elimination of the timeout contingency decreased the response rate to the timeout lever, but did not systematically affect DRL lever pressing. The rate of reinforcement appeared to be a primary determinant of the percent of session time spent in timeout periods.

Choice of timeout from fixed-time schedules: Comparison of two procedures

Behavioural Processes, 1997

Four rats obtained food on fixed-time (FT) 1-, 4-, and 16-min schedules. During FT schedules, a l... more Four rats obtained food on fixed-time (FT) 1-, 4-, and 16-min schedules. During FT schedules, a lever press produced a timeout period during which food could not be delivered. When timeout was in effect, a lever press ended the timeout period and reinstated the FT schedule. In different conditions, the timing of the FT interval either stopped for the duration of the timeout period (Stop condition) or the timing of the FT interval continued during timeout (No Stop condition). The percentage of session time spent in timeout periods increased as the time between food deliveries increased regardless of whether or not timing of the FT interval stopped during timeout. The timeout percentage was larger on Stop than No Stop conditions if the obtained interfood interval was also longer. The rate of initiation of timeout periods tended to increase from FT 1-min to FT 4-min schedules, and then not increase further or decrease on FT 16-min. The mean time per timeout period tended to be similar on FT 1-and FT 4-min schedules and then increase on FT 16-min. A given percentage of session time spent in timeout periods appears to be due to interactions between rate of timeout, duration of timeout periods and interfood interval. The data are not consistent with the suggestion that timeout initiation represents escape from aversive aspects of intermittent reinforcement. Instead, choice of timeout shares some of the properties of facultative behaviors.

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